RUNX2 and hypophosphatasia: Similar patients with severe CCD and features of hypophosphatasia have been described.(26, 27) The patient with severe CCD and hypophos‐phatasia described by El‐Gharbawy and colleagues(27) had a 50–70‐kb heterozygous deletion in the C‐terminal region of RUNX2, outside of the RUNT domain.